1. Field of the Invention
This invention relates to a filtering apparatus, specifically a reverse osmosis filter housing apparatus to facilitate easy removal and replacement of a filter housing from a mechanical support, and more specifically, to a push filter design that activates a floating key lock, where the key may be used simultaneously as a lock and as an identifier for particular filter attributes. The mechanical support may be situated inline, and in fluid communication, with influent and effluent piping. More specifically, the invention relates to a reverse osmosis filter housing and mount, whereby the filter housing may be attached to, and removed from, the mount by a push-actuated release. A controlled attachment or detachment of the filter sump, containing the filter media, is activated by the axial push of the sump towards the mechanical support. The specific key lock design allows a user to identify and match certain filter configurations received by the mechanical support, and reject other filter configurations. An internal shutoff, activated by the push-actuated release, blocks spillage during filter housing removal and replacement.
2. Description of Related Art
The invention relates to a water filtration system having a locking and unlocking mechanism for changing the filter when the filter media has served its useful life. The use of liquid filtration devices is well known in the art as shown in U.S. Pat. Nos. 5,135,645, 5,914,037 and 6,632,355. Although these patents show filters for water filtration, the filters are difficult to replace owing to their design and placement. For example, U.S. Pat. No. 5,135,645 discloses a filter cartridge as a plug-in cartridge with a series of switches to prevent the flow of water when the filter cartridge is removed for replacement. The filter must be manually inserted and removed and have a switch activated to activate valve mechanisms so as to prevent the flow of water when the filter is removed. The cover of the filter is placed in the sidewall of a refrigerator and is employed to activate the switches that activate the valves. The filter access is coplanar with the refrigerator wall and forces an awkward access to the filter cartridge.
In U.S. patent application Ser. No. 11/511,599 filed on Aug. 28, 2006, for Huda, entitled “FILTER HOUSING APPARATUS WITH ROTATING FILTER REPLACEMENT MECHANISM,” a filter assembly having a rotator actuating mechanism including a first internal rotator and a second internal rotator is taught as an efficient way to insert, lock, and remove the filter housing from its base. A simple push mechanism actuates the self-driving release and change over means that hold and release the filter housing or sump, and provide influent shutoff to prevent leaking and spillage. Rotational shutoff and locking mechanisms are activated and released by axial force on the filter housing at the commencement of the filter changing procedure.
The push-push design of the instant invention is particularly useful as the water filtering system for a refrigerator having water dispensing means and, optionally, an ice dispensing means. The water used in the refrigerator or water and ice may contain contaminants from municipal water sources or from underground well or aquifers. Accordingly, it is advantageous to provide a water filtration system to remove rust, sand, silt, dirt, sediment, heavy metals, microbiological contaminants, such as Giardia cysts, chlorine, pesticides, mercury, benzene, toluene, MTBE, Cadmium bacteria, viruses, and other know contaminants. Particularly useful water filter media for microbiological contaminants include those found in U.S. Pat. Nos. 6,872,311, 6,835,311, 6,797,167, 6,630,016, 5,331,037, and 5,147,722, and are incorporated herein by reference thereto.
The implementation of a push-push design for filter cartridge insertion and removal has not been employed in reverse osmosis systems. As discussed further herein, a reverse osmosis design requires an additional port, making the attachment scheme more complex than that of a simple filter cartridge system for typical refrigerator use.
Reverse Osmosis, a water treatment method traditionally known for removing salt from seawater, is also used to purify drinking water by forcing untreated water molecules through a semi-permeable membrane or filter. The membrane blocks contaminants and the impurities are subsequently expelled from the environment.
It is a process where a weaker saline solution will tend to migrate to a strong saline solution; that is, a solution that is less concentrated will have a natural tendency to migrate to a solution with a higher concentration. Reverse osmosis occurs when the solution is moved across a membrane against the concentration gradient, from lower concentration to higher concentration. For example, under normal osmosis, a semipermeable membrane with fresh water on one side and a concentrated aqueous solution on the other side would have the fresh water cross the membrane to dilute the concentrated solution. In reverse osmosis, pressure is exerted on the side with the concentrated solution to force the water molecules across the membrane to the lower concentration side.
A typical reverse osmosis water filtering system uses a semi-permeable membrane that has the ability to remove and reject a wide spectrum of impurities and contaminants from water. These contaminants are automatically rinsed down the drain. The purified water is then stored in a tank.
The predetermined pressure is applied to the incoming water to force the incoming water through the membrane. The membrane filters impurities from the incoming water leaving purified water on the other side of the membrane, which is referred to as “permeate” stream. The impurities left on the membrane are washed away by a portion of the incoming water that does not pass through the membrane. The water carrying the impurities washed away from the membrane is called “concentrate stream.”
Some of the benefits of employing a RO system include: pure, clean drinking water; removal of unwanted odors or tastes; and minimal maintenance. However, the extra port and additional water disposal means requires added complexity during attachment and detachment, which the present design facilitates
In the operation of reverse osmosis systems, the input liquid is divided into two output streams—the permeate stream which is substantially free of the dissolved substance and the concentrate stream which contains the majority of the substance to be removed. Reverse osmosis systems utilize a semi-permeable membrane with the input stream being fed at a pressure substantially above the osmotic pressure of the feed solution. When it is fed across the membrane, water molecules preferentially pass through the membrane with a very limited amount of the dissolved substances also passing through the membrane, depending upon the type of membrane and operation of the system.
Reverse osmosis is generally utilized in water purifiers after particulate/sediment filters and chlorine removal components/devices as a secondary or tertiary water purification technology employing a semipermeable membrane to remove very small particles and dissolved substances which may include microorganisms, as well as molecules of organic compounds of natural and man-made origin, charged species of elements such as calcium (Ca), magnesium (Mg), lead (Pb), arsenic (As), also ions such as carbonates, sulfates, chlorides, and the like, from drinking water. A semipermeable membrane is a membrane that will allow some atoms or molecules to pass but not others. Reverse osmosis can thus remove many types of molecules and ions from solutions, including microorganisms, and is used in both industrial processes and the production of potable water.
The water stream that carries the concentrated contaminants that did not pass through the RO membrane is generally referred to as the waste (reject or brine) stream.
The present invention employs the push-push design for cartridge insertion and removal to a reverse osmosis system.